Container



1. L. WILCOX v 3,195,795

\ CONTAINER Filed Aug. 20, 1965 July 20, 1965 FIG. 4 FIG. 5

INVENTOR.

ISAAC L. WILCOX.

HIS ATTORNEY.

United States Patent 3,195,795 CONTADIER Isaac L. Wilcox, Fulton, N.Y.,assignor, by mesne assignments, to Phillips Petroleum Company, acorporation of Delaware Filed Aug. 20, 1963, Ser. No. 303,960 3 Claims.(Cl. 229-7) This invention relates to containers made of sheet materialsuch as paperboard, and has to do particularly with the attachment ofthe end closure to the body of the container.

Several million of such containers are used daily for the retailpackaging of liquid food products, such as milk. It is most desirablethat the container embody a structural arrangement whereby an endclosure, particularly a top end closure may be quickly sealed in liquidtight relation and remain so sealed during handling of the filledcontainer, and at the same time be easy and convenient to separate, oropen to permit the contents of the container to be poured therefrom.

In order to render such containers, when formed of paperboard, to beentirely impervious to liquid, and to permit sterilization of thecontainers prior to filling, they are coated with plastic material, suchfor example, as polyethylene. The end closure may be quickly andconveniently permanently closed, or permanently bonded to the body ofthe container by the application of heat and pressure, the thermoplasticpolyethylene coating also acting as an adhesive for sealing the endclosures to the body of the container. However, such bonding is of apermanent nature and the overlapping, or engaging portions of the endclosure, or the body and the end closure cannot be subsequently readilyseparated, it being necessary to puncture, tear, or otherwise mutilatethe sealed parts to provide for the opening of the container to removethe contents therefrom.

In order to provide for easy opening of the sealed container in someinstances, an arrangement is employed to prevent a portion of theengaging parts from heatsealing together. This is accomplished byemploying a sealed barrier of some form between confronting portions ofthe engaging or overlapping parts to prevent those portions of the partsfrom fixedly bonding together.

Also, when such containers coated with thermoplastic material are open,and the liquid contents poured therefrom, there is a tendency for theliquid to trickle, or run down the exterior of the container.

This invention has as an object a container formed of sheet fibrousmaterial, such as paperboard coated with thermoplastic material torender the container impervious to liquids, and serving as an adhesiveto seal the engaging parts of the container closure, the container ofthe invention embodying a unique coating arrangement, whereby an area ofthe engaging parts of the end closure, or the end closure and body arebonded together in a restricted area by the heat-sealing operationemployed in closing the container, these engaging parts being bonded insuch manner as to be entirely leak-proof, and yet the parts bonded insuch area can be conveniently separated to provide a pour opening forthe removal of the contents of the container.

The invention has as a further object, the employment of a coatingarranged on the engaging, or overlapping parts of the container, whichwhen the parts are separated provides for the elimination of anytrickling, or run down of the contents on the outer surface of thecontainer.

The invention consists generally of a container formed of sheet materialhaving engaging parts coated with thermoplastic heat-scalable materialfor bonding the parts together. A portion of one of the parts isprovided with a coating of material non-heat-sealable to thethermoplastic material on said other part, the portion of said otherpart confronting said portion of the one part having bonded thereto in arestricted area a material heatsealable to the coating on said portionof said one part.

The invention consists in the novel features and constructions andmethod hereinafter set forth and claimed.

In describing the invention, reference is had to the accompany drawingsin which like characters designate corresponding parts in all the views.

In the drawings- FIGURE 1 is a view, in perspective, of a containerembodying my invention.

FIGURE 2 is an enlarged, sectional view taken on line 2-2, FIGURE 1.

FIGURE 3 is a view, with the portion of the top closure, shown in FIGURE2, separated from the side wall of the container.

FIGURE 4 is a plan view of the blank from which the container body isformed.

FIGURE 5 is a view, in perspective, of the top corner of the containerbody prior to the application of the top closure.

The container illustrated in the drawings is of the general typedisclosed in Patent No. 2,470,984, to R. H. Horning, et al., May 24,1949. It includes a body formed of paperboard, or like fibrous material.The body is formed is formed from the blank shown in FIGURE 4. The blankis provided with vertically extending scores 11 defining side wallpanels 12, 13, 14, 15 and 16. The blank is coated on both sides withthermoplastic material 20, the coating being bonded to the blank. Thesurface of the blank, constituting the outer surface of the containerhas printing applied thereto between the lines 21, 22. The blank isformed with an incision 23 extending lengthwise of the blank, and beingspaced slightly inwardly from one side edge thereof. The body blank issevered from a web moving continuously through the printing apparatus,and the printing cylinder, simultaneously with applying the printedmaterial between the lines 21, 22, prints a line 25 immediately abovethe incision line 23. This print line 25 extends laterally from one ofthe score lines, such as the score line 11, the print line extendingapproximately to the center of the adjacent side panels 13, 14, seeFIGURE 4. The purpose of the incision 23, and the print line 25 will beexplained hereinafter.

The blank is folded on the score lines 11 to square tubular form withthe free edge of the panel 16 overlapping the edge portion 27 of panel12, and being heat-sealed thereto by the thermoplastic coating 20. Asuitable bottom closure is bonded to the lower end of the tubular body.After the contents has been placed in the container, a top closure issealed to the top end of the body. This top closure is also formed offibrous material such as paperboard. The top closure is formed from aflat blank to provide a flat central area 29, dimensioned correspondingto the tubular body, and having at its periphery an upstanding flange 30extending upwardly inside of the top portion of the body, and outwardlyover the top edge of the body, and merges with a downwardly extendingouter flange 31. The top closure is also provided on its inner surfacewith a coating 33 of thermoplastic material, heatsealable to thecoatings 20 on the container body.

The flanges 30, 31 form an inverted channel positioned over the top edgeof the container body. Heat and pressure are applied to these flanges,whereby the flanges become permanently heat-sealed and bonded to thecontainer body by the coatings 20, 33.

In order to permit convenient opening of the closed container for theremoval of the contents therefrom, as

set forth in the Homing patent previously referred to, a

F I i n Veneer 95f {D ED I corner portion of the channel structure ofthe top closure was not heat-sealed to the container body. The bondingof this corner portion of thetop closure was prevented by aseal barrierpositioned. intermediate the corner por- 7 tion of the top closureflange, and the Contiguusportion.

of the container body. Such a seal barrierrna'y consist ofa stripofsheet'materia'l 37, such as'rnetallic foil. The

foil'strip 37 is heat-sealed, and bonded .to the inner sur-* faces; ofthe closure flanges: 30, 31 by the coating 33, on

these inner surfaces. The opposite side of the seal barrierunintentional separation ofthe'parts.

rier strip. The print line '25 is applied to a restricted area of thecontainer body, whereby the heat seal bond-- ing of the outer closureflange 31 to the body' is only in thisrestricted area." This restrictedarea of bonding of these engaging parts" is entirely sufiicient toprevent any On' the other hand, the restricted area does not require anyadditional effort in the opening'of the container." This is particularlytrue because of the'incision'line 23, which as previously pointed strip37 'has applied to-it, a coating 40 of material that isnon-heat-sealable' to the coatings on the body, and V accordingly, thefoilistrip sea-l barrier prevents one corner portion of the top closureflanges from sealing to the container body. It will be apparentthat thenon-scalable coating ,40 could be applied; directly to theinnersur'facesof the top closure flanges 30, 31,:but that arrangement would requirepattern,'or spot Jcoatingon the top closure,

or the body blank,if the non-scalable coating, were.ap-' plied thereto.It has beenfoundin practice, that the use I of the seal-barrier strip37' with the release or non-scal able coating 44) applied thereto is themore" practical an. 7,

rangement.

It will be understood that the seal barrier. strip 3 7Jextendsaboutacornerp'ortion of thexcontainer body, as the upper ends of 'the'panels,13,'14,Iand preferably extends downwardlyon the outer side of the bodybelow the flange 31 of the top closure, to provide'a free finger: griptab portion for assisting in movingthe flange 31 outwardly fromthecontainer body, and swinging the, corner portion of the top cl'o'sureupwardly, as shown in FIGURE 3; to

provide. the corner. pour opening for the removal. ofthe.

contentsfrom the container The flat central po'rtion29 of the topclosure may be provided with a score line43 extending diagonallyacros'sthe corner portion'of the top closure',;inwhich the seal barrier is"positioned, see FIG.- URE 1. factory separable top closure cornerportion, which, under normal handling. of the containers, remains inleakproof engagement with the contiguous top corner portion Thearrangement described, provides a satis} of the container body.-However, unusually rough hang dling of the filled container, or "theapplication of ap-- preciable pressure to thattop' corner portion oftheconj tainer tends to. effect premature separation betweenv the j topclosure, and'the container'at this onefsealed corner portion; If thecontainer is of larger ,capacity, such as gallon or half gallomand it ispicked up by grasping the top rim. of the container, thes'queezepres'sure at' the top may cause such premature leakage. However,this arrangement in general is particularly advantageousin that itprovides for easy and convenient opening of thecontainer, andwhenthiscorner portion ofthe top closure is V separated from the containerbody, and swung upwardly to provide. the pour opening, that exposedtop-edge of the container-body isste'rileinthat it has been previously Jcompletely protected by the top closure flanges.

By my invention, I modify the arrangement described to prevent anypremature separation ofthe topclosure from the container body withoutsacrificing the ease of" opening the container. I obtain thisadvantage'witho ut incurring any increase in the cost of the fabricationof the container. The print plate or cylinder for printing the exteriorof'the body blank between the lines 21, .22,

simultaneously applies the print line'25 to theblank. The ink used inthe printing operation after drying 'bonds firmlyto the thermoplasticcoating 20 on the body blank, and

after drying, this ink is 'heat-sealable'to' the coating 40 on the sealbarrier strip 37,.which as previouslyexplained is'bondedfto the innersurfaces ofthe'closure. flanges 30,

31,:hy thethermoplastic coatingZgS. In other.;Words, while the coating40 onthe'sealbarrier'fij isnoni-heat- 1 sealable with the coatings20 on.thecontainer body, the print line 25 bonded tothe outersurface' of thecontainer 'body ishea -sealablewiththe coating 40pm the seal barout,extends along the loweredgeof the print line 25. The print line 25 ispermanently bonded-to the outer. coating 20 of the container body, andthis coating in turn is permanently bonded to the container body, allwhereby when the flange 31 of the top closure is swung outward- 1y,the-print. line 25 and; the coating 20. bonded thereto movewith theflange causing a separation of the fibers.

in the outerlayer. of the containerbody'. v

r .Itwiil be apparent that the; incision line 23 aids material- 1yin,-the starting ofthis fiberseparation. This action is illustrated in;FIGURE 3 of the drawings, showing the coatinglli extending above theincision: 23 havingbeen separated fronrthe containerbody, leaving thesame with an'exposed fibrous surface, as indicated'at' 50. In other 7words, the strength'of thejbond bctweenthe' printline 25 and the"coating 20 exceeds-the. strength of the paperboard; when? the topclosure flange; :31: is intentionally moved-outWardlyfrom the containerbody forthe opening of the container, thisresulting in the" separationof. the" 7 layer fibers to which the body coatingZl) is bonded to.

separate from the paper-inthe sidewall of the container body. I havefoundthis area of exposed fibers on the outer surface of the containerbody at the top edge thereof, over which the contents of the containerare poured,

is effective to prevent any dribbling, or. ru'n cl own of the pouredmilk over the outer surface of the container body.

While the bonding of the print line 25 to the coatingi20 is sufficientto tear the coating from the containerbody,

the incision 23-assists greatly inthe'more'ready separation.

of the coating 29, and of the outer fibrouslayer of the containersidewall.

I The material for theicoating 20 may consist ofilow' density Alathon l5polyethylene, manufactured and sold by E. I. du Pont de emours & Co.,Inc., Wilmington, Delaware, Plastics Department. A material suitable forthe coating ti on the seal barrier strip 37 may consist of thefollowing: c r y 1 The ink used in printingv the exterior surface of thecontainer body, and including the print' line ZS'may'be a'flcxographic.inkforrnulated'of the following materials:

Cellulose nitrate I, Pigment Natural resins Synthetic resinsWaxcompounds r Proprietary .ethyl alcohol The coating 40 is applied Wetto the" seal barrier strip, and'upon drying, bonds firmly. thereto. Theprinting, in- ..cluding the print line-25, isappliedwet to theexteriorsurface of thecontainer body; and upon drying, bonds to the polyethylenecoating'20. After drying, the print line 25 isheat-sealable to thecoating 40.. Other, materials may be usedfor the coating 49 and the ink,if they are mutually heat scalable.

What I claim is:

i. A container formed of paperboard and having ongaging parts withcontacting surfaces, the entire surface of one engaging part beingcoated with a thermoplastic material, the major portion of thecontacting surface of said other engaging part being coated with likethermoplastic material for bonding the parts together, a strip of foilbonded to the remaining portion of said other part and having bonded toits surface confronting said one part,

a coating of material non-heat-sealable to the thermoplastic material onsaid one part, the surface of said one part confronting said foil beingprovided in a restricted area with a material overlying and bonded tosaid thermoplastic material on said one part, and being heat-sealable tothe coating on said foil.

2. A container formed of paperboard, including a body member and an endclosure member, said members having overlapping portions with contactingsurfaces, the entire contacting surface of the overlapping portion ofsaid body member being coated with a thermoplastic material, and themajor part of the contacting surface of the overlapping portion of saidclosure member being coated With like thermoplastic material forheat-sealing the parts together, the remaining'part of the contactingsurface of the overlapping portion of said closure member having bondedthereto a strip of metal foil, the surface of said foil confronting theoverlapping portion of said body member having bonded thereto a coating,including nitro cellulose material non-heat-sealable to thethermoplastic coating on the body member, the contacting surface of theoverlapping portion of said body member confronting said foil havingbonded thereto in a restricted area, a

coating, including nitro cellulose material, heat-scalable to thecoating on the confronting surface of the foil.

3. A container formed of paperboard and having first and second partswith contacting surfaces, the entire contacting surface of said firstpart being coated with a thermoplastic material, a portion of thecontacting surface of said second part being coated with a likethermoplastic material, said materials serving to join said coatedsurfaces by the application of heat and pressure, the remaining portionof the contacting surface of said second part having adhered thereto acoating of material nonheat-sealable to the thermoplastic material onsaid first part, the contacting surface of said first part confrontingsaid remaining portion of said second part being provided in arestricted area with a coating overlying said thermoplastic coating onsaid first part and being adhered thereto, said overlaid coating beingheat-scalable to the coating adhered on the said remaining portion onsaid second part.

References Cited by the Examiner UNITED STATES PATENTS 2,328,579 9/43Pelosi 2295.5 2,470,984 5/49 Horning et al. 229-7 2,471,017 5/49 Wilcox2295.5 2,802,613 8/57 Boyd 229-7 3,012,707 12/61 Gray 229-51 3,096,9187/63 Van Dyke et a1. 22951 FOREIGN PATENTS 562,5 86 9/58 Canada.

FRANKLIN T. GARRETT, Primary Examiner.

1. A CONTAINER FORMED OF PAPERBOARD AND HAVING ENGAGING PARTS WITHCONTACTING SURFACES, THE ENTIRE SURFACE OF ONE ENGAGING PART BEINGCOATED WITH A THERMOPLASTIC MATERIAL, THE MAJOR PORTION OF THECONTACTING SURFACE OF SAID OTHER ENGAGING PART BEING COATED WITH LIKETHEREMOPLASTIC MATERIAL FOR BONDING THE PARTS TOGETHER, A STRIP OF FOILBONDED TO THE REMAINING PORTION OF SAID OTHER PART AND HAVING BONDED TOITS SURFACE CONFRONTING SAID ONE PART, A COATING OF MATERIALNON-HEAT-SEALABLE TO THE THERMOPLASTIC MATRIAL ON SAID ONE PART, THESURFACE OF SAID ONE